Hello Following my previous message, I have not been able to track down the bug. What I noticed is that the stream error occurs after the loading of the std::string (on the next load operation), however the loaded string is not correct (eg, even if the exception is thrown later, the problem lies with the strings of length >= 512). Robert, if you cannot look into that, can you give me some pointers about where should I look to debug this problem? I am using a text archive. Hints about the implementation code would be useful for me. Thank you Jean-Noël